Not Applicable.
Reference to a xe2x80x9cComputer Listing Appendix submitted on a Compact Discxe2x80x9d.
A Computer Program Listing Appendix of the programming language for the present invention is provided on a write-only compact disc (CD), which is hereby incorporated herein by reference. Two copies of the CD are provided. The CDs are labeled Copy 1 and Copy 2. Each CD is entitled xe2x80x9cPart Tracking Patent Impact Engineering May 29, 2001xe2x80x9d and each CD is hereby incorporated herein by reference. Each CD, which has an IBM-PC machine format and is compatible with MS-Windows, contains the following 14 ASCII compliant files of the programming code of the arc-weld monitoring with part-tracking system of the present invention.
1. Network.cpp, which in its present format was created Apr. 10, 2001, and contains 126,980 bytes.
2. Network.h, which in its present format was created Mar. 30, 2001, contains 14,802 bytes.
3. Node.cpp, which in its present format was created May 21, 2001, contains 269,010 bytes.
4. Node.h, which in its present format was created Apr. 10, 2001, contains 27,184 bytes.
5. PartHist.cpp, which in its present format was created Jan. 24, 2001, and contains 8,890 bytes.
6. PartHistory.h, which in its present format was created Jan. 24, 2001, contains 4,386 bytes.
7. PartTrackingConfigDlg.cpp, which in its present format was created Jan. 24, 2001, contains 9,166 bytes.
8. PartTrackingConfigDlg.h, which in its present format was created Jan. 24, 2001, contains 4,564 bytes.
9. PartView.cpp, which in its present format was created Nov. 11, 2000, contains 11,439 bytes.
10. PartView.h, which in its present format was created Sep. 22, 2000, contains 3,648 bytes.
11. WkTrkDlg.cpp, which in its present format was created Dec. 11, 2000, contains 24,619 bytes.
12. WkTrkDlg.h, which in its present format was created Dec. 12, 2001, contains 3,524 bytes.
13. AdvancePartTrackingConfigDlg.cpp, which in its present format was created May 2, 2001, contains 6,000 bytes.
14. AdvancePartTrackingConfigDlg.h, which in its present format was created Jan. 24, 2001, contains 2,226 bytes.
The files are readable using an ASCII text reader such as Microsoft WordPad.
(1) Field of the Invention
The present invention relates to a weld monitoring system and method that monitors and automatically coordinates information on the quality of each weld in a workpiece having one or more welds. In particular, each weld in the workpiece is automatically analyzed at the time it is being made using weld sensors such as those that measure current, wire feed, voltage, and gas flow to produce information on the quality of the weld. Using this information, the welds are sorted, displayed, and logged with workpiece and weld number information which is provided to the operator in real-time and stored in a computer for access at a later time for quality control or other purposes. Therefore, the system and method enables welds of a quality less than a pre-determined quality for the weld to be identified in real-time and information concerning any particular weld to be accessed at a later time.
(2) Description of Related Art
Many high volume, complex welded assemblies are produced using manual or semi-automated production welders. The repetitive nature of these welding operations and the high production rates that are required eventually lead to welder fatigue. Therefore, missing or defective welds on these welded assemblies is a major quality assurance problem. Missing or defective welds can lead to structural failure of the welded assemblies which can be catastrophic for downstream users of these welded assemblies.
To identify defective welds, sensors that measure current, wire feed, voltage, and gas flow are used to enable the quality of a weld to be determined. The information produced by the sensors allows defective welds or welds of a quality less than a pre-determined quality to be identified. The following U.S. Patents exemplify the state of the art in controlling or monitoring the quality of welds made in a welding operation.
U.S. Pat. No. 4,503,311 to Houchens et al. discloses a method and apparatus for detecting the onset of melting in a resistance spot weld, which enables the prediction of weld quality to be determined. The method measures the weld resistance at many points during the formation of the weld, storing those resistance values, calculating a rate of change of resistance curve from the stored resistance values, locating the maximum rate of change of resistance occurring prior to the resistance peak and locating the time subsequent to the maximum rate of change that the rate of change curve reaches a specified fraction of its maximum, which time occurs at the knee of the resistance curve which approximates the onset of melting.
U.S. Pat. No. 5,245,546 to Iceland discloses a welding arc length control system. The system includes a power source for providing welding current, a power amplification system, a motorized welding torch assembly connected to the power amplification system, a computer, and a current pickup means. The computer is connected to the power amplification system for storing and processing arc weld current power source and to the welding torch assembly for providing weld current data to the computer. Therefore, the system maintains the desired arc length as the welding current is varied during operation, which maintains consistent weld penetration.
U.S. Pat. No. 5,510,596 to Xu et al. discloses an arc welding device apparatus for controlling an arc welder through use of a neural network in real-time. The invention also records output from an arc welding apparatus indicating whether penetration has occurred during the welding process and can also activate an alarm when penetration occurs during the arc welding process, which indicates that the weld is solid.
U.S. Pat. No. 5,932,123 to Marhofer et al. discloses a mobile automated pipeline welding and quality control system comprising a gas metal arc welding carriage and a weld data monitor and acquisition unit. The system comprises a welding machine for welding pipes and a weld monitor consisting of, inter alia, a current detector for detecting welding current applied to the welding torch, a voltage detector for detecting welding voltage, and a travel speed detector for detecting the travel speed of the welding machine. The weld monitor includes a memory, a micro-processor for successively recording the detected current, voltage, and travel speed parameters in the memory, and means for specifying the recording intervals of the parameter. The weld monitor displays one or more of the detected parameters in substantially real-time.
U.S. Pat. No. 6,064,029 to Choi et al. discloses a method and apparatus for controlling the quality of a resistance spot weld. The method estimates the quality of a spot weld by using a nugget penetration of the resistance spot weld and a nugget size, which are estimated by using the Hidden Markov Model method.
U.S. Pat. No. 6,140,825 to Fujii et al. discloses a method and apparatus for evaluating quality of a resistance weld. The method measures instantaneous values of welding current to determine the quality of the weld as it is being formed.
While the above methods are capable of determining the quality of a weld and present information about the quality of the weld, the above methods do not automatically track and verify a series of independent welds performed by one welder or robot on one or more workpieces in a welding operation for producing a welded assembly and present the information after the weld is made to the welder in real-time to enable the welder to take appropriate remedial action. Nor do the above methods coordinate the information from a series of welds on one or more workpieces in one or more welding operations and display the information graphically for each weld in each of the welded assemblies wherein the quality of each of the welds is displayed superimposed on an image for each of the welded assemblies, which enables in an inspection process to determine which of the welded assemblies pass or fail a quality control inspection.
The present invention provides a weld monitoring system and method that monitors and automatically coordinates information on the quality of each weld in a workpiece having one or more welds. In particular, each weld in the workpiece is automatically analyzed at the time it is being made using weld sensors such as those that measure current, wire feed, voltage, and gas flow to produce information on the quality of the weld. Using this information, the welds are sorted, displayed, and logged with workpiece and weld number information which is provided to the operator in real-time and stored in a computer for access at a later time for quality control or other purposes. Therefore, the system and method enables welds of a quality less than a pre-determined quality for the weld to be identified in real-time and information concerning any particular weld to be accessed at a later time.
In particular, the present invention provides a method for welding components of a workpiece with multiple arc welds in a fixture using a consumable electrode wire, melting the wire by heat from an electric arc having a current and voltage which comprises: (a) providing a system with the fixture having (i) one or more weld sensor means for detecting a quality of each weld on the workpiece on the fixture for welding the workpiece; (ii) a program in a computer to continuously monitor the output from the one or more weld sensor means; and (iii) a switch means connected to the computer for starting a period during which the multiple welds are monitored and then completed and for terminating the monitoring; (b) placing components which form the workpiece in the fixture, welding the workpiece with the multiple welds, while determining the quality of each weld; and (c) removing the workpiece from the fixture, wherein the program in the computer provides monitoring of each of the multiple welds by means of the one or more weld sensor means between the starting and terminating of the monitoring by the switch means. Preferably, the method provides the monitoring in real-time and for later analysis.
In particular embodiments of the method, the weld sensor means is selected from the group consisting of a sensor that measures the voltage of the arc, a sensor that measures the current between the components of the workpiece and the wire being welded, a sensor that measures the rate of gas flow, and a sensor that measures a rate of feed of the wire to the arc.
In further embodiments of the method, the multiple welds are performed as simultaneous multiple welds or the multiple welds are performed in series.
The method is useful wherein the welding is performed manually or is performed by computer controlled robotic welders.
Preferably, the program in the computer provides a completion or fault signal for each of the multiple welds. More preferably, the program in the computer provides a completion or fault signal for each of the multiple welds with a display of the workpiece and the multiple welds on a computer display screen so that individual welds of the multiple welds are shown as completed or having the fault.
In a further embodiment of the method, the switch means is activated or deactivated as a result of opening or closing of a holding means on the fixture for holding the component parts during the welding.
In an embodiment further still of the method, in addition the program transfers the weld data to a second computer system programmed for receiving a series of weld data for multiples of the workpieces and for selective analysis of the weld data. Preferably, the second computer has a computer display screen which provides a visual display, a printer which provides a printout, or both of the weld data for each of the multiple of the workpieces.
The present invention also provides a system for monitoring welding of components of a workpiece with multiple arc welds in a fixture using a consumable electrode wire, melting the wire by heat from an electric arc having a current and voltage which comprises: (a) one or more weld sensor means to be mounted on equipment for the welding; (b) a computer with a program to continuously monitor output from the one or more weld sensor means and to provide weld data to the computer; and (c) switch means connected to the computer for starting a period during which the multiple welds are detected by the one or more weld sensor means and monitored by the computer and for terminating the period, wherein the system is used with a fixture with a holding means for welding the components into the workpiece and wherein the program monitors each of the welds for a fault by means of the one or more weld sensor means between the starting and terminating of the monitoring by the switch means. In particular embodiments, the switch means are started and stopped by opening and closing the holding means which are clamps. Preferably, the system provides the monitoring in real-time and for later analysis.
In a particular embodiment of the system, the weld sensor means is selected from the group consisting of a sensor that measures the voltage of the arc, a sensor that measures the current between the components of the workpiece and the wire being welded, a sensor that measures the rate of gas flow, and a sensor that measures a rate of feed of the wire to the arc. In a further embodiment, the switch means is activated or deactivated as a result of opening or closing of a holding means on the fixture for holding the components during the welding.
In a particular embodiments of the system, the system is adapted for monitoring welds produced by one or more computer controlled robots for the welding.
Preferably, in the system the computer provides a weld completion or fault display on a computer display screen. More preferably, the computer provides a weld completion or fault display on a computer display screen with a display of the workpiece and the multiple welds so that individual welds are shown as completed or with the fault.
In an embodiment further still, the system provides a second computer system which is programmed for receiving a series of weld data for multiples of the workpieces and for selective analysis of the weld data. Preferably, the second computer has a computer display screen which provides a visual display, a printer which provides a printout, or both of each of the multiples of the workpieces.
Finally, the present invention provides in a system for monitoring in a welding operation quality of multiple welds on a workpiece using one or more weld sensors at the location of each of the multiple welds wherein the one or more weld sensors provide information relating to the quality of each weld as it is being made on the workpiece, the improvement comprising: a control means in the system, which determines the start of the multiple welds on the workpiece and the end of the multiple welds on the workpiece or measures a duration of time the workpiece is to be acted upon in the welding operation; and a computer program in the system which monitors the multiple welds on the workpiece between the start and the end and coordinates information relating to the quality of each weld in the multiple welds and displays the information.
In particular embodiments, the multiple welds are monitored by the system simultaneously or are monitored in the system in series and further wherein the monitoring is where the welding is manual or where the monitoring is of welds made by one or more computer controlled robotic welders. Preferably, the program in the computer provides a completion or fault signal for each of the multiple welds. Most preferably, the program in the computer provides a completion or fault signal for each of the multiple welds with a display of the workpiece and the multiple welds on a computer display screen so that individual welds of the multiple welds are shown as completed or having the fault on the computer display screen. It is further preferable, that in addition the program transfers the weld data to a second computer system programmed for receiving a series of weld data for the workpiece and for selective analysis of the weld data, in particular wherein the second computer has a second computer display screen which provides a visual display of the weld data, a printer which provides a printout of the weld data, or both of the workpiece.
In particular embodiments of the system, the weld sensor means is selected from the group consisting of a sensor that measures the voltage of the arc, a sensor that measures the current between the components of the workpiece and the wire being welded, a sensor that measures the rate of gas flow, and a sensor that measures a rate of feed of the wire to the arc.
Therefore, it is an object of the present invention to provide for a welding operation for producing a welded assembly, a system that tracks and automatically coordinates information on the quality of each weld in a workpiece having a plurality of welds wherein each weld in the workpiece is automatically analyzed at the time it is being made using sensors such as those that measure current, wire feed, voltage, and gas flow to produce information on the quality of the weld which is presented to the operator in real-time and stored in a computer for analysis and for quality control inspection wherein each of the welds of the welded assembly are superimposed on an image of the welded assembly and ranked according to the welds relationship to a predetermined quality.